The present invention relates to a bale handling apparatus, a so-called bale ejector or thrower, including a pan positioned for receiving a completed bale, as it is pushed from a bale-forming case of a baler by material being compacted for forming the next bale, and for throwing the bale through the air into a trailing wagon towed by the baler, and more specifically, relates to a system for controlling the bale thrower.
In a known bale ejector, pressurized fluid is routed to a hydraulic throwing cylinder for causing the cylinder to quickly extend and operate a pan suspension linkage for causing the pan to go through a throwing motion so as to propel a bale, resting on the pan, through the air. A spool valve is used for controlling passage of the pressurized fluid to the cylinder, this valve including a spool having an exposed end to which a trip bar is coupled. Actuation of the valve is accomplished through a trip linkage coupled between the trip bar and a trip pedal, the latter being positioned for contact by a bale when correctly positioned on the pan for launch. A reset linkage operates in response to pan movement to reset the trip linkage for the next cycle. A manually-operable lockout bar is provided for selectively preventing operation of the throwing cylinder, as when shields for preventing bystanders from entering the launch zone are raised for permitting service, for example. The distance through which the cylinder will cause a bale to be thrown may be varied by operation of an adjustable relief valve which adjusts the pressure of the fluid routed to the throwing cylinder.
The known bale thrower suffers from the drawbacks of the exposed valve spool being subject to corrosion during extended periods of non-use and of the various linkages for controlling operation of the valve spool requiring adjustments which are difficult to make and/or to understand. Improper adjustment may result in the hydraulic valve becoming damaged causing it to malfunction resulting in additional damage and associated costs.
U.S. Patent No. Re. 27,657, issued on Jun. 5, 1973 to Soteropulos, discloses a basic bale ejector design featuring a pan suspended on throwing arms caused to be moved through a throwing motion by a hydraulic cylinder actuated in response to actuation of a control valve through the action of a valve control linkage operated by a trip pedal pivoted by a bale as it becomes properly positioned on the throwing pan.